Cellulose acetate fibers having wool dyeing properties and a spinning solution therefor



.of fabric.

Patented Apr. 6, 1948 cELLULosa aca'ra'ra mans navmo WOOL nnzmoraoraa'rms AND A x SPINNING SOLUTION THEREFOR John R. Caldwell,Kingsport, 'lenn., assignor to Eastman Kodak Company,

Rochester, N. Y., a

corporation of New Jersey No Drawing. Application June 14, 1.945,v

Serial u ssaszz 1 Claims. (01. 106-186) This invention relates to themanufacture of synthetic fibers from lower fatty esters 'of cellulose,whichlfibers are susceptible to dyeing by wool dyestuffs.

In the textile industry it is often desirable to use fibers of differentkinds in the manufacture After the fabric has been woven, it may then besubjected to a dyeing operation and it is often desirable that thefibers have dyeing properties which are substantially equivalent.

In those fabrics in which cellulose ester fibers are combined with thefibers of natural wool, it has commonly been necessary heretofore toemploy both an acetate dyestufi and a wool dyestuff to impart color tothe fabric. In many cases considerable difilculty has been encounteredin matching the shades of the wool fibers and the cellulose esterfibers. In addition, the two types of dyestuffs often responddiflerentlyto laundering, light-fading; etc., resulting in fabrics having a spottyor irregular appearance after they have been exposed to conditions ofwear.

Many attempts have been made heretofore to impart wool dyeing propertiesto cellulose ester fibers but the results obtained have not been toosatisfactory. the dyeing of wool fibers by acid type dyestuffs takesplace through the reaction of the sulfonic acid groups in the dyemolecule with amine groups in the wool to form a salt linkage. To impartwool dye aifinity totcellulose ester fibers, compounds have beenincorporated therein having basic amino groups, resembling those presentin natural wool. In most cases heretofore the fibers which have been soprepared would take up only small amounts of dyestufl to give aweakshade, or the dye employed to dye the cellulose ester fibers wouldshow poor stability toward lightfa-ding and laundering. 7

It is an objectof my invention to prepare fibers of lower fatty estersof cellulose having good susceptibility to acid dyes and good stability,when so dyed, to fading by light or by laundering. Other objects of myinvention are apparent herein I have found that fibers may be preparedfrom lower fatty acid esters'of cellulose bearing a very closeresemblance to wool in their behavior toward acid type dyestuffs. I havefound that cellulose -ester fibers may be prepared which when dyed inthe same bath with wool are so colored that the shade produced is a.close match for the color on the wool both as to depth and shade. Ihavefound that fabrics made from wool in combination with the lower fattyacid esters of The idea commonly held is that cellulose fibers producedin accordance with my invention may be union dyed in an acid type wooldyebath to produce a uniform color, free of spots or irregularities.

In its broadest aspects my invention comprises incorporating incellulose ester fibers a small proportion ofa polymeric amine having thestruc-} l in which R is an alkyl radical having 1-4 carbon atoms.

R is a hydrocarbon radical having 2-4 carbon atoms and of a structuresuch that at least two carbon atoms separate the N and O.

R" is a saturated or unsaturated hydrocarbon radical containing 1-8carbon atoms.

m is a whole number greater than 6.

I have found that this polymeric material may be incorporated in thecellulose ester fibers either by treatment 'of the fiber after'itsformation with a solution of the polymer in an organic solvent orpreferably by incorporating the polymer in the cellulose ester fibers byadding it directly to the spinning dope. I have found that the polymeris completely compatible with the cellulose ester so that they form ahomogeneous system and that the polymer forms an insoluble com-' plexwith the acid dyestuif;

The linear polymericamines employed in the process of the invention aremost conveniently prepared by the interaction of dibasic acids withalkyl-dialkylol amines having the general structure: R

ing tertiary amine groups in the main valence chain. The alkyl-dialkylolamines, which are useful in my process, include ethyl diethanol amine, I

methyl diethanol amine, methyl diisopropanol amine, butyl diethanolamine HO--CHzCH,N-C:H4.OH

H: H: and

In general any dibasic acid containing 3-10 carbon atoms is suitable.Thedibasic acid may are radicals as-defined heretofore. The polymer isformed by the eliminaether or the like.

'lose ester is dissolved.

for use in accordance with my invention are malonic acid, succinicacid,glutaric acid, alpha methyl glutaric acid, adipic acid, sebacicacid, and the like. Oleflnic dibasic acids which may be employed arerepresented by maleic acid and fumaric acid. Aromatic dibasic acidswhich may be employed include phthalic acid, teraphthalic acid, 2-methylphthalic acid or similar phthalic acid derivatives. Either the freeacids, their anhydridcs, or their esters may be employed as the startingmaterials for the reaction with alkyldialkylolamine in preparingpolymeric amines for use in my invention.

The formation of the polymeric amines by reacting the dibasic acid andalkyl-dialky-lol amine may be carried out by heating the reactants underconditions that allow the escape of water. The acid and the amine may beheated in a suitable vessel with agitation. either with or without apolymerizationcatalyst. If desired, the reacting materials may be heatedin the presence of an entraining liquid to remove water by azeotropicdistillation. Suitable entraining liquids are benzene, toluene, xylene,kerosene, dibutyl The preparation of the polymeric aminesmay be carriedout within the range of 110200 C., but it is preferred to use atemperature of 150-175 C. for this purpose. It is ordinarily desirableto carry out the polymerization reaction to a point where the polymerhas an equivalent weight as an acid, of 5,000- 10,000 although polymershaving equivalent weights above or below this range are often suitablefor use in my invention. The course of the reaction may be followed .bytitration of samples of the reacting mass with standard alkali inalcohol solutions, using phenolphthalein as the indicator.

The most desirable means of preparing cellulose ester fibers inaccordance with my invention is by dissolving the polymeric amines inthe spinning dope which consists ofa solution of the cellulose ester ina volatile solvent. Ordinarily the solvent employed for spinningcellulose ester is acetone, and the polymeric amines may be dissolvedtherein at the same time as the cellu- It is to be understood, however,that other solvents may be employed for spinningcellulosc esters, and myinvention also includes cases using other solvents in which thesepolymeric amines are incorporated. To secure good affinity for wooldyes, the cellulose ester fibers should contain Ill-30% of the polymericamine.

Instead of incorporating the polymeric amines in the spinning dope, itmay be applied to the cellulose ester fibers from its solution in anorganic solvent such as alcoholor benzene. I have found, however, that amore uniform dispersion. of polymer throughout the fiber cross sectionisobtained in those cases where the polymer is incorporated directly intothe spinning dope.

My invention is adapted to impart a wool dyeing property to the variouslower fatty ester acids of cellulose which have been employed for.preparing synthetic fabrics. For instance, cellulose acetate which hasbeen hydrolyzed to an acetyl content of 39-40% is much employed,especially in acetone solution for making synthetic fibers. Also othercellulose esterssuch as cellulose acetate propionate or celluloseacetate butyrate having a propionate or butyrate of 1 to 6% such as 4described in U. S. Patent No. 2,223,376 of Maim are of interest in thiscase. Also cellulose esters having an even higher propionate or butyratecontent may be employed. My invention applies to the fibers preparedfrom any of these cellulose esters. By my invention, fibers are preparedtherefrom which are susceptible to dyeing by any of the wool dyestuflscontaining sulfonic acid groups in the dye molecules. The followingexamples illustrate my invention:

Example I 146 grams of adipic acid and 133 grams 01" 0 m-cm-u-c Hr-CHz-Q-C 0-c.H.-c 0-0-) It. was a pale yellow oil, soluble in alcohol,acetone, and benzene. It was insoluble in water,

soluble in dilute acids, and thrown out of acid solution by the additionof sodium hydroxide.

A spinning dopewas prepared having the composition; 25 parts celluloseacetate having an acetyl content of, 39%, 4 parts of the polymeric amineand 75 parts of acetone. Fibers were spun from this solution byextruding it through a spinning cabinet under evaporative conditions.The resulting fibers dyed to a dark even shade in the followingdyejbath: 2 parts LRC Tinting Blue (Color Index No. 671), parts ofwater,

5 parts of sodium sulfate and 10 parts of acetic aci Example 11 Amixture was prepared consisting of 133 grams of N-ethyl diethanolamine,100 grams of succinic anhydride, and 100 cc. xylene. This mixture washeated in an esteriflcation apparatus for 20-24 hours. Approximately 18cc, of water was eliminated. The xylene was removed under a vacuum toleave a residue of light yellow, viscous oil. The resulting polymer hadthe structure A sample dissolved in alcohol and titrated with standardsodium hydroxide showed an equivalent weight of 10,000-14,000. Thepolymeric amine formed was soluble in acetone, alcohol, and benzene. Itwas soluble in dilute acids and may be thrown out of solution by alkali.

A spinning dope was prepared consisting of 25 parts of celluloseacetate, 5 parts'of the polymeric amine, and '75 parts of acetone. Yarnwas spsn from the solution by an evaporative process as referred to inthe preceding example. The resulting fiber was found to dye'well withLRC Tinting Blue (Color Index No. 671), National Tinting Yellow NCL(Color Index No. 640), Na-

tional Alkali Fast Green 2G- (Color Index No.

"735), and Acid Green 2G (Color Index No. 670).

. of a polymeric amine which is a viscous oil having the formula:

(-R -i -W-O co-rw-c o-'-o) R i I m in which R is an alkyl radical having1-4 carbonpolymeric amine being no more than 14,000.

2. Cellulose ester fibers having wool dyeing properties essentiallyconsisting of cellulose acetate and approximately 10-30%, of a polymericamine, which isa vicsose oil having the formula:

in which R is an alkyl radical having 1-4 carbon atoms, R. is asaturated hydrocarbon radical having 2-4 carbon atoms, and of astructuresuch that at least 2 carbon atoms separate the .N and O, R" is'asaturated hydrocarbon radical containing 1-8 carbon atoms, and mis awhole number greater than 6 the equivalent weight of the polymeric aminebeing no more than 14,000.

3. Cellulose ester fibers having wool dyeing properties essentiallyconsisting ofra lower fatty acid ester of cellulose and approximately10-30%, of a viscous oil consistingof the polymer of a dicarboxylic acidand ethyl diethanolamine.

4. Cellulose ester fibers having wool dyeing properties essentiallyconsisting of cellulose acetate and approximately 10-30%, of a viscousoil consisting of a polymer of a dlcarboxylio acid and ethyldiethanolamine,

5. A spinning solution essentially consisting of 10 taining 1-8 carbonatoms, and m is a whole number greater than 6 theequivalent weight ofthe a lower fatty acid ester of cellulose and approximately 10-30%, of apolymeric amine a viscose oil having the formula:

which is in which R is an alkyl radical having 1-4 carbon atoms. R is asaturated hydrocarbon radical having 2-4 carbon atoms, and of a.structure such that at least 2 carbon atoms separate the N and O. R" isa saturated hydrocarbon radical containing 1-8 carbon atoms, m is awhole number greater than 6 the equivalent weight of the polymeric aminebeing no more than 14.000, and sufllcient acetone to completely dissolvethe cellulose ester and the pol m amine- 6. A spinning solutionessentially consisting of cellulose acetate and approximately lit-30%,of a polymeric amine which is a viscous oil having the formula:

containing 1-8 carbon atoms, m is a whole number greater than 8 theequivalent weight of the polymeric'amine being no more than 14,000, andsumcient acetone to completely dissolve the cellulose ester and thepolymeric amine.

. 7. A spinning solution essentially consisting of .cellulose acetate.approximately 10-30%, of a viscous oil consisting of a. polymer ofdicarboxylic acid and ethyl diethanolamine and suflicient acetone tocompletely dissolve the cellulose acetate and the polymer.

JOHN R. CALDWEIL.

